@if(!Request.IsAuthenticated) {
    @Html.ActionLink("Register", "Register", "Account") 
    @: | 
    @Html.ActionLink("Login", "Login", "Account")
}
else {
    @: Welcome <b>@User.Identity.Name</b>!
    
    @: |
    @Html.ActionLink("Logout", "LogOff", "Account")
}